This document discusses the importance of enterprise architecture (EA) for IT planning and business transformation in the aircraft maintenance, repair and overhaul (MRO) industry. It provides 5 rules for leveraging EA to add business value: 1) Know where you are now, 2) Articulate the business strategy and goals to know where you are going, 3) "All do some" not "some do all" when capturing changes, 4) Collaborate and communicate to enable enterprise decision making, and 5) Use enterprise tools to transform enterprise capabilities and realize change. The document emphasizes that EA should be owned by the business, not IT, and provides frameworks and best practices for developing and implementing an effective EA.